What a cool HS project! I'll bet the kids are looking forward to getting their hands on your 'bolt.
As to adjusting the valves, your old shop manual will have the procedure for adjusting solid lifters since that's all the 216 came with, but with the later 235 there's a possibility that you have hydraulic lifters, completely different procedure. There's been several posts here about how to tell what you have, try doing a search and see what pops up.
